There have been proposed combined air-conditioning and hot-water supply systems that are equipped with a heat pump cycle and are capable of simultaneously providing an air conditioning load and a hot water load. As one of such systems, there has been a combined air-conditioning and hot-water supply system capable of simultaneously providing a cooling load, a heating load, and a hot water load with such a configuration that a hot-water supply refrigerant system including a compressor, a water heat exchanger, an expansion device, and a refrigerant-to-refrigerant heat exchanger is cascade-connected to part of a condenser of an air-conditioning refrigerant system including a compressor, an outdoor heat exchanger, an expansion device, an indoor heat exchanger, and an accumulator (see Patent Literature 1, for example).
There has also been disclosed a combined air-conditioning and hot-water supply system that “includes an outdoor unit having a compressor configured to compress refrigerant, a plurality of indoor units connected to the outdoor unit and configured to condition air, a water heater connected to the outdoor unit and configured to supply hot water, operation detecting means that detects an operational states of each of the plurality of indoor units, and controlling means that controls the operating capacity of the compressor in accordance with the detection results of the operation detecting means while maintaining a predetermined operating capacity required by the water heater” (see Patent Literature 2, for example).